thump at no volume

[beastyle 10+ year member]

Fiat problem.... At first I had two external amps and one in a sealed box, the one in the sealed box didnt allow remote bass controll (only on the box itself) so I added a caliber rc unit and stashed it in the dash...

The sub's frequenty and gain level are all the way up so that I can set it correct through the caliber unit however (it does work) I have an annoying thump and have CD switching noises (only if frequenty is real low) when the volume is low

I know how to fix it (cant change grounds, and grounds are clear, also multimeter indicates that grounding has little enough resistence), but I want to know why it occured in the first place, can it be because there's a shitload of RCA underneath my radio and on top of the caliber unit ? The unit is about 5 x 5cm and has two rca in and two rca out's.

I tried solving it with an LT2 filter which basically is an ground loop isolator and indeed the sound was gone, the confusion remains because it cannot be the ground //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

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[chris229 10+ year member]

Originally posted by beastyle Fiat problem.... At first I had two external amps and one in a sealed box, the one in the sealed box didnt allow remote bass controll (only on the box itself) so I added a caliber rc unit and stashed it in the dash...

cool!

The sub's frequenty and gain level are all the way up so that I can set it correct through the caliber unit

This isn't a good idea cause you will be raising the noise floor of your 'caliber unit'

however (it does work) I have an annoying thump

a turn on thump is due to a UPSTREAM processor coming on after the AMP. This means the AMP must be delayed untill after THAT processor. A turn-off thump would be due to a up stream processor turning off BEFORE the AMP and the processor must be delayed.

and have CD switching noises (only if frequenty is real low) when the volume is low

This is due to a bad gain structure and it must be reset to the proper 3/1 overlap or a 10dB overlap

I know how to fix it (cant change grounds, and grounds are clear, also multimeter indicates that grounding has little enough resistence), but I want to know why it occured in the first place, can it be because there's a shitload of RCA underneath my radio and on top of the caliber unit ? The unit is about 5 x 5cm and has two rca in and two rca out's.

playing with your grounds has been found by the surgeon general to cause insomnia, increased blood pressure, short tempers and violent fits of rage and a low precentage of stroke. Leave them alone

I tried solving it with an LT2 filter which basically is an ground loop isolator and indeed the sound was gone, the confusion remains because it cannot be the ground //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

I know man. It isn't

 

[beastyle 10+ year member]

hrm

If you dont turn your amp's gain and frequenty up to the roof then I wont be able to set it up front because when I put full output on at the RC then the amp is still only at half or even less.

The wicked part is that when the hertz level on the RC is 140 or over the thump is near gone. Its kinda matching with your statement that the amp is pushing to much shit to the RC or something

To me it still smells like some "lack of buffer problem"....

Anywayz, I got the LT2 filter again today and the thumps are gone so my confusion is back alive (lt2 only resolves ground problems so it must be a ground problem in some way after all and i'm thinking that the "ground" in question is an overload to the RC)